Apparatus for grinding or polishing glass.



No. 792,564. PATENTED JUNE 13, 1905. P. L. 0. WADSWORTH.

APPARATUS FOR GRINDING 0B. POLISHING GLASS.

APPLIOATION FILED 00T. e, 1903.

UNITED STATES `ratentecl June 13, 1905.

ATnNT trice.

FRANK L. O. WADSIVORTH, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO PRESSEDPRISM PLATE GLASS COMPANY, OF MORGANTOV N, WEST VIRGINIA, A CORPORATIONOF VEST VIRGINIA.

APPARATUS FOR GRINDING OR POLISHING GLASS.

SPECIFICATION forming part of Letters Patent No. 792,564, dated June 13,1905.

Application filed October 6, 1903. Serial No. 175,966.

Be it known that I, FRANK L. O. IVADswon'ru, of Allegheny,Alleghenycounty,Penn sylvania` have invented a new and useful Apparatus forGrinding or Polishing Glass, of which the following is a full, clear,and exact description, reference being had to the accompanying'drawings, forming part of this specification, in which Figure l is avertical central section showing one form of apparatus embodying myinvention, and Fig. 2 is a partial top plan view of the same.

INI y invention relates to the grinding or polishing of glass plates orsheets, and is designed to provide an effective apparatus by which bothsides of the glass are ground or polished simultaneously.

A further object of the invention is to provide mechanism for actingupon both faces of the glass in such a manner that the frietional forcestending to move the glass in its own plane are substantially equal andopposite on its opposite sides in every part of the glass.

In the drawings the upper disks 47 and the lower disks LIS are providedwith hollow shafts extending through stationary bearings in plates 49and 50. The hollow shafts 5l for the upper disk are preferably providedwith collars 52, carried at the inner ends of the counterweightcd levers53. The weights on these levers partially counterweight the disks, whichwould otherwise bear too heavily on the upper vface of the sheet. I haveshown the rings 52 as having ball-races containing balls engaged by hubson the sprocket-wheels 54, secured to the upper ends of the hollowshafts. The upper disks are simultaneously driven in the .same directionby a sprocketchain 55, which extends around the sprocketwheels 54, asshown in Fig. 2, and around an idler-sprocket 56 and a driving-sprocket57 The sprocket-wheels 58 for the lower shafts are provided with asprocket-chain extending around a driving sprocket-wheel 59, secured toa counter-shaft 60, having gearing connection 61 at its top with theshaft of the sprocketwheel 57. The upper and lower disks are thusrotated in opposite directions. The glass sheet 62 is held betweenremovable separate 50 plates 63, which are bolted to an outer frame 64,entirely surrounding the sheet and which rests upon a surroundingstationary bed-plate 65. The frame 64 may be moved in any suitablemanner, and I have shown it as adapted to be moved by hand, it beingrecessed on the under face to receive ball 66, resting on the bed-plate.This 'frame does not in any way support the glass, which rests of itsown weight on the lower disks. The upper portions of the hubs of thesprocket-wheels 54: are preferably formed in funnel shape to receive theabrading material fed through spouts 67 from a longitudinal receptacleor hopper 68. In this horizontal form the frictional force exerted onthe lower face of the glass would be greater than that upon the upperface, owing to the weight of the sheets, and to make these forcessubstantially equal i may provide different forms of mechanism. It maybe accomplished by driving the lower disks at a lower rate of speed thanthe upper disks. In the form shown I accomplish this result byconnecting the hollow shafts of the lower disks with the Yfeed-box 69,to which leads a pressure-supply pipe 70. The abrading material forthelower disks is mixed with a liquid, such as water, and is forced inunder pressure, this pressure being graduated so that its lifting actionon the sheet of glass will cause it to substantially float between theupper and lower disks, so that the frictional forces are substantiallyalike on both faces. To assist in this action, I may use an Archimedeanscrew 7l in the cylindrical feed-box 69 and havingits shaft 72 extendingthrough a stuffing-box in the end and driven through a suitableconnection. In using this form the upper and lower disks are driven inopposite directions, and the abrading material feeds through the uppershafts by gravity, while it is forced upwardly under pressure throughthe hollow shafts ot' the lower bed. The vtrictional forces are thussubstantially equalized, and the plate-'frame may be moved by theattendant, or driving mechanism used to cause an equal action on itsdifferent portions.

The advan tages ot' my invention result from the simultaneous grindingof both sides of the glass without danger et' breakin g or crackingthereof. The abrading action is equalized on all parts and theAii'ictional forces are substantially neutralized. The delay ofembedding' the glass is avoided and the temperature of the glass on bothsides is substantially the same, so that the danger ot' breakage owingto this difference of temperature is obviated.

Many variations may be made in the form and arrangement ot' theapparatus without departing from my invention, since I consider myselffirst to act upon both Vt'aces and at the same time substantiallyequalize the frictional forces.

I claim-H 1. In glass grinding or polishing apparatus a `pair of diskslying in approximately horizontal planes, mechanism foi-driving thedisks in opposite directions, and means for holding a glass sheetbetween the disks; substantially as described.

2. In glass grinding or polishing apparatus a pair et' disks lying` inapproximately horizontal planes, mechanism for driving the disks inopposite directions, means for holding a glass sheet between the disks,and means for varying' the pressure oi' the upper disk on the glass;substantially as described.

3. In g'lass grinding or polishing apparatus a pair or' disks lying inapproximately horizontal planes, mechanism for driving the disks inopposite directions, means for holding a glass sheet between the disks,and means for 'forcing an abrasive mixture uiiiwardly against the lowerface of the glass sheet; substantially as described.

4. In glass grinding or polishing apparatus a pair et' disks lying inapproximately horizontal planes, mechanism for driving the disks inopposite directions, and means vfor holding a glass sheet between thedisks, said means being arranged to allow the sheet to be moved indifferent directions; substantially as described.

5. In glass grinding or polishing apparatus a plurality of pairs ot'disks arranged in substantially horizontal planes and opposing eachother, mechanism vfor driving the disks in opposite directions, thelower disks being' arranged to receive a glass sheet resting thereon,and means Vfor feeding the abrading material to the upper and lowerfaces oi'l the plate; substantially as described.

In testimony whereo t' I have hereunto set my hand.

FRANK L. O. WADS WORTH.

Iitnessesz Geo. B. BLEMING, JOHN MILLER.

